Subbu,
First question I'd ask is what is the business requirement for all plant to have the same Structure Indicator?
Existing plant users will be happier if you maintain the same labelling. Users will be better served if you perform a data cleansing exercise rather than rely on the classification system. From my experience adding to the SAP system landscape or upgrading is best performed with the same rigour as a new implementation.
- Concentrate on the intent of standard SAP functionality until that is exhausted.
- If you actually need to have one edit mask for the enterprise start numerically with 00-00-00 etc to ensure the structure is correct. Remember - too much inteligence in the TOS is not an inteligent thing to do!
Alternative labelling caould be used, but why would you?